UC Irvine

In the USA, yearly, over 1.7 million patients acquire infection during their hospital stay; about 99,000 of them died. The only cure and prevention currently in use are antibiotics; however, more severe infections have been seen in the past decade because of the development of microbial resistance to antibiotics. We have discovered that it is possible to engineer a nanopatterned surface that can kill and/or prevent the growth of microbes by mimicking nature’s antibacterial surfaces. Others have explored top-down approaches, such as lithography and anodization to fabricate an array of nanopatterned surfaces. Limitations for such an approach are the size of the template and types of surfaces. Here, I describe the use of a self-assembled microstructured polymeric surface coating that is inherently biocompatible and designed to overcome the problems described above. The desired surface is coated with LPEI (linear polyethylenimine), a hydrogel that undergoes water-induced crystallization. By controlling the solution pH and concentration, the simple dip-coating method can be used to fabricate coatings with nanostructure possessing well-defined morphology and tunable geometry on any arbitrary surface. Using material characterization techniques and rheometer, an insight to LPEI macromolecules behavior in the solution to promote pillar-like morphology formation can be described. Specifically, I focused on gaining an understanding of the effect of the cohesive behavior of LPEI macromolecules and the interaction of the polymer with water in controlling such morphology. Our grand vision is to be able to engineer an effective, long-lasting, and biocompatible coating layer to prevent device-associated infection around the world.